Note: Descriptions are shown in the official language in which they were submitted.
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ICEBREAICTNG ~F~IP
~CItGROUpD OF,-,SHE INV~_ Di
1. Field of the Inventions
The invention concerns an ioebreaking ship having a forward
quarter designed like a pontoon with the underside of the bow
extending frown the ship bottom roughly to the beginning of the
front third of the baw and rising obliquely forward to above the
water line. The lateral edges of the bow in the vicinity of the
water line bear icebreaking ax' cutting means and the width of the
~.eebreaking or cutting means in the vicinity of the water line is
greater than the width of the water line of the afterbody of the
hull. The hull can also have balcony-like flanks on both sides,
with a parapet that is preferably oriented roughly vertically.
The balcony undersides adjoining the parapet can be oriented
obliquely downward and the balcony support adjoining oblique
surfaces, until the transition to the essentially flat ship
bottom, can be oriented roughly vertically. The water line of
the hull runs roughly parallel, and preferably somewhat outward
to the half width of the underside of th! baloony.
:~. Background Informationa
Icebreakers of this type, which were disclosed in German
Patent 4101034, have recessed waistline-like indentatioas in the
body of the ship on both sides adjoining the pontoon-like forwatd
r~uarter .
Furthermore, in this known icebreaker, the balcony-like
flanks adjoining the indentations extend all the way to the
:~tern.
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It is true that, with appropriate dimensions of depth and
length, the waistline-like indentations provide a small turning
circle radius during turns of the ship and, cons~quently, good
maneuverability; however, such indentations roquir~ significant
construction interventions in the struoture of the ship's hull
a,nd, consequently, increased cost.
Moreover, said indentations disrupt the flow of water
currents along the ship's side, which circu~astanc~ has a disad~
vantageous effect on resistance, particularly during forward
travel in ice-free waters.
O8J8CT Of THE INVB~iTI1?DT
The object of the invention is to overcome these
deficiencies and accordingly to improve the design of an
icebreaker such that the isebreaker requires no oomplex
structural forms of the ship's hull, and furthermore has so
flow-restricting elements.
SUMMARY OF T8E I~IVE~tTIQ~i
This object is achieved by the present invention in as
icebreaking ship having balcony-like flanks which extend the
entire length, or virtually the entire length of the hull of the
ship. These flanks preferably do not have any indentations
therein directed toward the interior of the ship, and the flanks
preferably run essentially parallel to the longitudinal axis of
the ship. The ship preferably has balcony supports, or side wall
portions of the hull, below the balcony-like flanks, while the
hull portion has at the desk level, or top thereof, a parapet
extending along each side of the ship above the balcony.
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The width of the underside of the bow at its starting point,
or the bottom of the ship, corresponds roughly to the distance
from the balcony support on one aids of the ship to the balcony
support on the other side of the ship. From the starting point
forward, the bow widens continuously until reaching the width of I
the underside of the bow in the vicinity of the water line. In
the bow portion of the hull, the distance from the parapet on one
side of the ship to the parapet on the other side is preferably
greater than the width of the underside of the bow in the
vicinity of the water line.
The above-discussed feature of the present invention, in
addition to the advantages mentioned, achieve several additional
astonishing effects, in that the icebrsaking or cutting means
disposed on the lateral edges of the bow can improve course
stability during travel in a broken ice channel and can also
.improve the ease of turning in curved travel because of~thetr
autwardly angled position relative to the longitudinal axis of
the ship.
Known icebreaker ships have bean able to actively break the
.ice with at least one of the bow or stern portions. To achieve
turning capability, these icebreakers have bean built with a
:Lsnticular water line, i.e., without a parallel center section,
or with a very short parallel center section.
Because of this lenticular water line, and the resultant,
irregularly broken edge of the ice, and partially also because of
additional improvements in the design of lateral projections on
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the bow and possibly even on the stern, such known icebrsaking
ships can travel in circles using forces on their rudds=~
The present invention is based on the idea that icebrsaking
means are present not only on the bow and stern, but essentially
extend along preferably the entire length of the icebreaker on
the ship's sides. This icebreaker according to the present
invention is thus completely surrounded by iasbrsakiag means,
i.e., at p=efsrably every point of its water line.
Using the transverse farces generated by the control
elements (rudders), the icebreaker of the present invention is
preferably capable of breaking ice in the forward quarter area on
the inside of the curves, and both midships, and in the stern
area on the outside of the curves as well. This capability is a
function of the transverse forces of the control elssasnts, and of
the slope of the underside of the balcony and of the ice
conditions, such as thickness and solidity.
Rnown icebreakers have a bulkhead angle of incidence of 0
degrees to a maximum of approximstely 25 degrees from vertical.
With sufficiently thick ice, this bulkhead angle of incidence is
too small to br~ak ice via they sides of the ship during curved
travel using the transverses farces of the control elements. The
above-mentioned small angles of incidence should essentially only
serve to reduce the forees exerted by the ice when the ice
presses against the ship.
Several variant embodiments of the present invention are
summarised herebelow.
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The underside of the bow for the icebreaker of the present
invention can be designated so that the underside of the bow
above and below the water line perpendicular to the longitudinal
axis of the ship is flat, slightly bowed, or flexed to thereby be
particularly advantageous for breaking a straight ice channel.
Further, the underside of the bow can be designed so that between
its starting point on the ship bottom to above the water Line,
each side is preferably flexed upward at an angle such that
longitudinal lateral faces are produced. Such a design enables
centering of the ship more readily in its ice channel.
Further, the lateral edges of the underside of the bow can
preferably be beveled and/or rounded, so that the slide-off of
the ice clods from the icebreaking means, either into the channel
between the bottom of the balcony and the balcony support, or
under the underside of the bow should be faoilitated.
Also a bottom clearing wedge can be disposed on the ship
bottom, preferably below the water line, and preferably in the
vicinity of the starting point of the underside of the bow to
divert ice clods which have made their way under the bottom of
the bow to the sides of the ship. This design protects the drive
and control elements astern against contact with ice to increase
their level of efficiency andlor to protect them from damage.
Also, by designing the forward quarter of the hull to
continuously widen toward the base, the distance from the parapet
to the parapet must b~ greater than the width of the underside of
the bow in the vicinity of the water line, since with this
measure the distance from the underside of the balcony to the
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underside of the bal~.ony is also increased in this area.
The icebreaking ship according to the present invention can
also be equipped with a device for generating and sustaining a
swaying motion of the ship essentially around its central
.':ongitudinal axis. :4s such, the turning behavior of the ship can
be indirectly improvad since, as a result of the swaying orations,
the breakup of the edge of the ice is intensified by the oblique
underside of the balcony, particularly during turning.
One aspect of the invention resides broadly in a ship for
breaking ice to clear a channel through an ice field, the ship
having a hull, said hull having a bow, a stern, a length
extending from said bow to said stern, first and second sides
extending from said bow to said stern, and a width between said
first and second sides, said hull comprisingr icebreaking means,
said icebreaking means extending across a width of said bow and
along a substantial portion of the length of said hull along each
of said first and second sides thereof; said hull is fox being
disposed in water to a depth defined by a water line, and said
icebreaking means being disposed at least in the vicinity of the
water line; said first and second sides of said hull have a first
wall portion disposed below the water line, a second wall portion
disposed above the water line, and a connecting portion
connecting said first wall portion to said second wall portion;
said connecting portion being disposed substantially along said
water line of said ship; said hull having a first width at said
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first wail portions, and a second width at said second wall
portions, said first width being less than said second width;
said connecting portion comprising said icebreaking means along
each of said first and second sides; each of said first wall
portions and said second wall portions are disposed substantially
vertically; and said connecting portion is disposed obliquely
downward between said first wall portion and said second wall
portion at an angle of about 30°.
Another aspect of the invention resides broadly in an
icebreaking ship having a bottom, a hull, a forward quarter
designed like a pontoon, a bow, an afterbody disposed sternward
behind the bow, and a longitudinal axis, the hull comprising: a
first side and a second side disposed in a spaced apart relation
with respect to one another and extending along the afterbody;
the bow having an underside extending from the ship bottom at
roughly the beginning of a front third of the ship and rising
obliquely forward to above the water line; the bow having lateral
edges in the vicinity of the water line, said lateral edges
comprising icebreaking means; both the afterbody and the bow
having a width in the vicinity of the water line, the width of
t:he bow in the vicinity of the water line being greater than the
width of the,afterbody in the vicinity of the water line; first
side wall portions disposed below the water line and projecting
flanks disposed above the water line on both of the (first and
second sides of the hull; said projecting flanks on both of the
first and second sides comprising a parapet portion oriented
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roughly vertically, and said first side wall portions being
oriented roughly vertically; said projecting flanks comprising an
underside portion adjoining the parapet portion, the underside
portion being oriented obliquely downward towards the first side
wall portions; the underside portions having a width extending
from the first side wall portions to the parapet portion, and the
ship water line runs roughly parallel, preferably somewhat
outward, to a half-width of the underside portions of the
projecting flanks; said projecting flanks extend along at least a
substantial portion of the length of the hull, have no
indentations directed toward the interior of the ship, and run
essentially parallel to the longitudinal axis of the ship; the
underside of the bow having a first width at its starting point
on the bottom of the ship, and the hull having a second width
extending from the first side wall portion on the first side of
the hull to the first side wall portion on the second side of the
hull; the first width corresponding roughly to the second width,
and from the starting point of the bow on the bottom of the ship,
forward, the underside of the bow widens continuously to reach
the width of the underside of the bow in the vicinity of the
water line; and the hull has a third width extending Pram the
parapet on the first side of the hull to the parapet on the
second side of the hull, said third width being substantially a
width of an upper deck of the ship, and said third width being
greater than the width of the underside of the bow in the
vicinity of the water line.
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Yet another aspect of the invention resides broadly in a
ship for breaking ice to clear a channel through an ice field,
the ship having a hull, said hull having a bow, a stern, a length
extending from said bow to said stern, first and second sides
extending from said bow to said stern, and a width between said
first and second sides, said hull comprising: reamers for
breaking ice disposed on said lateral edges, said reamers
extending across a width of said bow and along a substantial
portion of the length of said hull along each of said first and
second sides thereof,.
A further aspect of the invention resides broadly in an
i.cebreaking ship having a hull, a bow and a ship bottom, the ship
also having an interior disposed inside the hull of the ship and
a.n upper deck disposed above the hull of the ship, the
i.cebreaking ship having a forward quarter which forward quarter
(P) is designed like a pontoon, the bow of trie ship having an
underside, the underside having a portion comprising
substantially the front third of the underside of the bow of the
ship, the underside of the bow extending from the ship bottom
roughly to the beginning of the portion of the underside and
rising obliquely forward to above the water line, the underside
of the bow having lateral edges, the lateral edges of the
underside of the bow in the vicinity of the water line bear
icebreaking or cutting means (reamers) and whose width in the
vicinity of the water line is greater than the width of the water
line of the afterbody, the hull has two sides disposed opposite
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to one another whereby the hull has balcony-like flanks on both
sides of the hull, the sides of the hull each having a parapet
which is oriented substantially vertically, the balcony underside
adjoining it is oriented obliquely downward and the balcony
support adjoining it until the transition to the essentially flat
ship bottom is oriented roughly vertically, and whereby the water
line rune roughly parallel, preferably somewhat outward, to the
half width of the underside of the balcony, characterized in that
the balcony-like flanks extend substantially the entire length of
the hull (R) and have no indentations directed toward the
interior of the ship and run essentially parallel to the
longitudinal axis of the ship, that furthermore the width of the
underside (5) of the bow at its starting point on the ship bottom
(4) corresponds roughly to the distance from the balcony support
(3) of one side to the balcony support (3) of the other side and
from there forward widens continuously until it reaches the width
of the underside (5) of the bow in the vicinity of the water line
(SWL), and that the distance from the parapet of one side {1') to
the parapet (1') of the other side and thus the width of the
upper deck (7) is greater than the width of the underside (5) of
the bow in the vicinity of the water line (SWL).
BRIEF DESCRIPTION OF T8E DRAWINGS
The object of the invention as well as several variants are
illustrated in detail in the. accompanying drawings. The drawings
depict, in each case, a perspective view, with a plurality of
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profile curves distributed over the length of the ship illustrated.
in the drawings:
Figure 1 shows a ship's hull designed according to the
present invention with the underside of the bow continuously flat
in the transverse direction and with largely straight flanks;
Figure 2 shows a ship's hull designed according to the
present invention with the underside of the bow flat in the
transverse direction and the lateral edges bowed outwards; and
Figure 3 shows a ship's hull designed according to the
present invention with lateral faces bent upward in the
transverse direction along the lateral edges of the underside of
the bow.
6e
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In all figures, the sane parts o! the iaebreaksr are
provided with the sane reference symbols.
The letter R generally refers to the icebreaker's hull, the
starboard silo of which is depicted in all of the figures with a !
plurality o! profile curves dirtributed ove= along the leaqth of
the ship. Based on these profile lines it oan be seen that the
flanks of the ship are shaped like a balcony. In essence, the
balconies extend along substantially the satire length of the
ship, and even along the stern area. ~"urther, with the exoeption
of a slight widening o! the forward quarter toward the bow, the
balconies run generally parallel to the longitudinal axis o! the
ship.
It can also be seen that the parapets 1, 1' are roughly
vertical and the adjoining balcony undersides 2, 2' are '
preferably oriented obliquely downward at an eagle of
approximately 30 degrees. The adjoining balcony supports 3,
which also represents the flank of the stern and which
essentially makes a transition to the flat bottom ai the ship,
are likewise essentially vertical.
The forward quarter, referenced as a whole by the letter P,
is preferably designed like a pontoon, or in other words, the
underside 5 of the forward quarter P is preferably roughly
perpendicular to the longitudinal center plane of the ship, and
essentially extends on both sides of this plane. p'urther, the
andereide along this forward quarter P preferably rises obliquely
from th~ bottom of the ship 4 to the bow.
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The area where the underside 5 of the bow starts out from
the bottom 4 of the ship is preferably located roughly in the
front third of the length of the ship, and the transition from
the bottom 4 of the ship to the underside 5 of the bow can
preferably be a continuous or s~aoth transition.
In this transition area, the underside 5 of the bow can
preferably hays the width of the balcony support 3, and the
lateral edges 5' of the underside 5 can thus snake a transition
into the curve 9 located between the balcony supports 3 and the
bottom 4 of the ship. The underside 5 of the bow also prefesably
gradually widens~towards the front, until it finally essentially
matches the width of the hull at the parapet 1'.
~n the area where the underside 5 of the bow intersects the
water line, hereinafter abbreviated gWL, the lateral edges 5' are
preferably designed as icebroakir~g mean's, which, together with
the underside 5 of the bow, break a channel with essentially
straight linear ice edges in a sheet of ice. The continuous
widening of the underside 5 of the bow is preferably s~le~ated
such that the distance between the lateral edges 5' in the
vicinity of the 9f~lh is slightly larger than the width in the SiPi.
for the rest of they hull R. disposed there behind. i
In the variant according to figure 1, the lateral edges 5'
of the underside 5 of the bow in the vicinity of the S'WL
essentially form a straight line extending from the bottom 4 to
the parapet i'. In the variant according to Figure 2, the
lateral edges 5' essentially represent outwardly bowed curves.
,.
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In both variants, the underside 5 of the bow is the vioinity
of the SwL, and at right angles to the longl.tutdinal axis o! the
ship, is essentially flat, and in the area thereunder, is
slightly flexed dawna~ardly. This downward flexion essentially
aan provide a good transition to a bottom clearing wedge 6 which
begins in the vicinity of this downward flexion and expands in a
v-shape aft. The branched e~ctat~sions b' of the olearinq wedge 6
essentially provide a transition into the balcony supports 3.
In the variant aooording to higure 3, this design is
somewhat altered is that the underside 5 of the bow is provided
on each side over its entire length with lateral faxes 5 " angled j
upwardly relative to their center surfaoe. The lateral facts 5 "
are delimited by the edges 5 " ' and the lateral edge 5', both of
which edges 5 " ' and 5' provide a transition to the bottom 4 in
S
the ourve 9.
As alread mentioned in all variants the distance between
Y r
the parapets 1' preferably increases slightly in the area of the
fos~ard quarter F and, consequently, the width of the upper deck
7 can also invrease in a similar manner, roughly fro~a the
beginning of the forward quartex p, continuously toward the bow.
This increase in width thereby allows the distanoe between
the undersides 2' of the baioonies in this area to be increased
accozdingly.
It is thus comarnon to all variants that the channel which the
underside of the bow breaks in the ice is somewhat wider than the
width of the SWZ of the afterbody R such that a clearanoe remains
between the aftezbody R and the edges of tha ice of the channel.
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This clearance can thereby prevent a possible jaaaning-in of the
hull R.
Another variant, not shown, but significant within the
framework of the invention, provides the icebreaking ship of the
present invention with an arrangement for generating a swaying
motion of the ship essentially around its central longitudinal
axis. Such arrangements are generally known in the art. 8y
providing such a swaying motion, additional breaking forces can
be transmitted from the undersides 2, 2' of the balconies to the
edges of the ice. The ice can thereby be broken by the balconies
and the clearance between the edges of th~ ice and the hull R can
be widened. This widening increases the turning capability of
the ship in the ice.
All, or substantially all, of the components and methods of
the various embodiments may be used with at least one embodiment
or all of the embodiments, if any, described herein.
The invention as described hereinabove in the context of the
preferred embodiments is not to be taken as limited to all of the
provided details thereof, since modifications and variations
thereof may be made without departing froaln the spirit and scope
of the invention.
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y~7lF~ GER'iIFIC~ai
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